Improvement in head-blocks for saw-mills



UNITED STATES PATENT OFFICE..

C. LEFFINGWELL, OF OLARKSBURG, ASSIGNOR TO HIMSELF, H. BLANDY, AND F. J.'L. BLANDY, OF ZANESVILLE, OHIO.

IMPROVEMENT IN HEAD-BLOCKS FOR SAW-MILLS.

Specification forming part of Letters Patent No. 56,145, dated July 3,1866.

To all 'whom it may concern.'

Be it known that I, C. LEFFINGWELL, of Clarksburg, in the county of Rossand State of Ohio, have invented a new and Improved Head-Block; and I dohereby declare that the following is a full, clear, and exactdescription thereof, which will enable others skilled in the art to makeand use the same, reference being had to the accompanying drawings,forming y part of this specification, in which- Figurel is a top or planview of my improved head-block, part being broken away to show theconstruction. Fig. 2 is an under-side view of the same. Fig. 3 is avertical section taken through the line w a', Fig. l. Fig. 4 is averical sectional view taken through the line y y,

Similar letters of reference indicate like parts.

My invention has for its object to furnish an improved head-block forsaw mills so constructed that the timber may be moved quickly andaccurately, however short the required distance may be 5 and itconsists, first, in the construction and arrangement of the pawlblocks;and, second, in the combination of the rods, levers, and racks, by meansof which the knees of the head-blocks are worked, with each other andwith the movable pawls, as hereinafter more fully described.

A is the frame of the machine. B are the slides upon which the headblocks O slide. These slides B are grooved upon both sides, and in thegrooves thus formed are placed racks D and E. The racks D are immovablyattached to the slides B, or they may be made solid therewith, asrepresentedin the drawings. rIhe other rack, E, is movable, and slidesback and forth in the groove in which it is placed.

To the sides of the head-block C are attached the pawls F, which actupon the rack in the manner hereinafter described. These pawls arerhomboidal in form, as shown in Fig. l, and they slide up and down ininclined channels in frames G, in which they are placed. The pawls F arekept in their placesin the frames G by pins f attached to said pawls andprojectingdownward through slots form ed in the under side of saidframe, as shown in Figs. 2, 3, and 4. The Ypawls are raised, whenrequired, by means of a stirrup, H, which passes around the frame Gbelow the pins f', and is pivoted at its upper side to the end of alever, I. This lever is pivoted to a support, J, on the upper side ofthe block G. By depressing the free ends of the levers I the pawls F arelifted away from the racks E and D, and the blocks O may be moved backto their former position.

K is a lever pivoted to a support, L, attached to one side of the frameA. The lower end of' this lever is connected by a rod, M, to the ends oftwo rods, N and O, which slide in guides in the side of the frame A. l

P is a bent lever, the long arm of which is connected to the rod or barN by the connecting-rod B, and its other end is connected by theconnecting-rod S to the movable rack E. The bent lever T is connected tothe rod O by the rod U, and to the movable rack E by the rod V.

In using the machine, by moving the upper end of the lever K to theright in Fig. 4 the motion is communicated through the rods and leversto the movable rack E, moving it forward until the forward end of therack E comes in contact with the stop X, leaving the timber in theproper position to be sawed. This forward movement of the racks Ecarries the headblock C forward with said racks, the pawls Fsliding overthe teeth of the stationary rack D. By moving the lever K to the leftthe racks E are drawn back a distance regulated by the adjustable stopsW. `The stops W are pins, against which the rear ends ofthe racks Estrike as they are moved back. These pins W are set in holes formed inthe sides of the slides B, and so arranged that by moving these stopsfrom one hole to another the racks E may be made to advance at eachforward movement the exact distance required. If only one pawl F isused, the length of each advance of the racks E would necessarily equalthe distance apart of the teeth of the said rack E, or some multiple ofthat distance; but by increasing the number of the pawls and making thedistance between the bearing-surfaces of the pawls vary from thedistance apart of the teeth of the movable rack, and by graduating theholes for the stops W according to this variation, the forward movementof the headblooks C may be made equal to the distance apart of the teethof the rack E and the distance apart of the pawls F, or equal to anymultiple of that distance.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is

l. The paWl-blocks C G F H I, when constructed and arrangedsubstantially as herein described, and for the purpose set forth.

2. The combination of the lever K, rod M,

